Apparatus and method for transmitting inter-working signal in wireless communication system

1. A method for transmitting cell information by a femto Base Station (BS) of a small cell in a wireless communication environment in which a communication system of a large cell and another communication system of the small cell are hierarchically configured in the same area, the method comprising:

receiving, by the femto BS, transmission information from a macro BS of a large cell;

identifying a transmission interval in the received transmission information; and

transmitting a reference signal using an operating frequency of the macro BS at the transmission interval,

wherein the reference signal includes femto BS information, and

wherein the femto BS is located within a service area of the macro BS.

2. The method of claim 1 , wherein the femto BS information comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of the femto BS, a frequency channel number of the femto BS, a preamble sequence index of the femto BS, a signal bandwidth of the femto BS, service level prediction information that can be provided by the femto BS, operation state information of the femto BS, and active mode transition information of the femto BS.

3. The method of claim 1 , wherein transmitting the reference signal comprises transmitting the reference signal using a whole or a portion of the operating frequency of the macro BS during the transmission interval.

4. The method of claim 1 , wherein the transmission interval is set using a partial resource of a frame comprising the transmission interval.

5. A method for handover of a Mobile Station (MS) in a wireless communication environment in which a communication system of a large cell and another communication system of a small cell are hierarchically configured in the same area, the method comprising:

communicating with a macro base station (BS) of the large cell;

receiving a reference signal from a femto BS of the small cell using a whole or a portion of an operating frequency of the macro BS at a transmission interval determined by the macro BS;

determining a femto BS information of the femto BS through the reference signal; and

performing a handover to the femto BS using the femto BS.

6. The method of claim 5 , wherein the femto BS information comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of the femto BS or a frequency channel number, a preamble sequence index of the femto BS, a signal bandwidth of the femto BS, service level prediction information that can be provided by the femto BS, operation state information of the femto BS, and active mode transition information of the femto BS.

7. The method of claim 5 , further comprising:

after confirming the femto BS information, confirming operating state information of the femto BS using the femto BS information;

when the femto BS operates in a power saving mode, making the femto BS transit to an active mode; and

when the BS operates in the active mode, performing a handover to the femto BS.

8. The method of claim 7 , wherein making the femto BS transit to the active mode comprises requesting the macro BS for active mode transition of the femto BS of the small cell.

9. The method of claim 7 , wherein making the femto BS transit to the active mode comprises requesting the femto BS for active mode transition.

10. The method of claim 5 , wherein the handover comprises:

performing scanning using the cell information;

deciding whether to perform handover according to the scanning result; and

when deciding to perform handover, performing handover to the femto BS selected by the scanning.

11. An apparatus configured to transmit cell information in a femto Base Station (BS) of a small cell in a wireless communication environment in which a communication system of a large cell and another communication system of the small cell are hierarchically configured in the same area, the apparatus comprising:

a reference signal generator configured to generate a reference signal for the femto BS;

a scheduler configured to schedule, during a transmission interval, transmission of the reference signal using an operating frequency of a macro BS of the large cell; and

a transmitter configured to transmit the reference signal using the operating frequency of the macro BS during the transmission interval according to the scheduling information,

wherein the reference signal includes femto BS information,

wherein the BS is located within service area of the macro BS, and

wherein the transmission interval is identified in transmission information received from the macro BS.

12. The apparatus of claim 11 , wherein the reference signal generator is configured to generate a reference signal that comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of the femto BS or a frequency channel number, a preamble sequence index of the femto BS, a signal bandwidth of the femto BS, service level prediction information that can be provided by the femto BS, operation state information of the femto BS, and active mode transition information of the femto BS.

13. The apparatus of claim 11 , wherein the transmitter is configured to transmit the reference signal using a whole or a portion of the operating frequency of the macro BS during the transmission interval.

14. The apparatus of claim 11 , wherein the transmitter is configured to transmit the reference signal during the transmission interval that is set using a partial resource of a frame comprising the transmission interval.

15. An apparatus configured to perform a handover of a Mobile Station (MS) in a wireless communication environment in which a communication system of a large cell and another communication system of a small cell are hierarchically configured in the same area, the apparatus comprising:

a receiver configured to receive a first signal;

a transmitter configured to transmit a second signal;

a reference signal analyzer configured to:

determine a femto base station (BS) information of a femto BS of a small cell through the reference signal when communicating with the macro BS of a large cell, wherein the reference signal is received from the femto BS using a whole or a portion of an operating frequency of the macro BS at a transmission interval determined by the macro BS, and

a controller configured to control the handover to the femto BS using the femto BS information.

16. The apparatus of claim 15 , wherein the reference signal analyzer is configured to acquire, from the reference signal, the femto BS information that comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of the femto BS or a frequency channel number, a preamble sequence index of the femto BS, a signal bandwidth of the femto BS, service level prediction information that can be provided by the femto BS, operation state information of the femto BS, and active mode transition information of the femto BS.

17. The apparatus of claim 15 , wherein, when the femto BS is configured to operate in a power saving mode according to the acquired femto BS information, the controller is configured to:

control the femto BS to transit to an active mode, and

when the femto BS operates in the active mode, perform a handover to the femto BS.

18. The apparatus of claim 17 , wherein, when the controller controls the femto BS to transit to the active mode, the controller is configured to request the macro BS for active mode transition of the femto BS.

19. The apparatus of claim 17 , wherein, when the controller controls the femto BS to transit to the active mode, the controller is configured to request the femto BS for active mode transition.

20. The apparatus of claim 15 , wherein, when acquiring the femto BS information from the reference signal analyzer, the controller is configured to scan a neighbor cell using the femto BS information, decide whether to perform handover according to the scanning result, and, when deciding to perform handover, perform a handover to the femto BS selected by the scanning.